Semiconductor device and manufacturing method of semiconductor device

ABSTRACT

Even in a case where a pad becomes smaller, solder connection strength is improved. A semiconductor device includes a pad, a diffusion layer, and a melting layer. The pad included by the semiconductor device includes a concave portion on a surface at which solder connection is to be performed. The diffusion layer included by the semiconductor device is disposed at the concave portion and constituted with a metal which remains on the surface of the pad while diffusing into solder upon the solder connection. The melting layer included by the semiconductor device is disposed adjacent to the diffusion layer and constituted with a metal which diffuses and melts into the solder upon the solder connection.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 17/499,166, filed Oct. 12, 2021, which is acontinuous application of U.S. patent application Ser. No. 16/765,332,filed on May 19, 2020, now U.S. Pat. No. 11,183,472, which is a nationalstage entry of PCT application No. PCT/JP2018/039008 filed on Oct. 19,2018, which claims priority benefit of Japanese Patent Application No.JP 2017-227414 filed in the Japan Patent Office on Nov. 28, 2017. Eachof the above-referenced applications is hereby incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present technology relates to a semiconductor device and amanufacturing method of a semiconductor device. More particularly, thepresent technology relates to a semiconductor device including a pad atwhich solder connection is to be performed, and a manufacturing methodof a semiconductor device.

BACKGROUND ART

In related art, a semiconductor device in which a plurality ofsemiconductor chips is laminated and implemented has been used. Forexample, a semiconductor device in which a second semiconductor chip isimplemented on a first semiconductor chip is used. In this semiconductordevice, the first semiconductor chip is electrically connected to thesecond semiconductor chip by tin (Sn)-based solder. A microbump isformed by solder on a rear surface of the second semiconductor chip.Meanwhile, a bump pad in a concave shape which is fitted to themicrobump of the second semiconductor chip is formed on a surface of thefirst semiconductor chip. At a bottom portion of the bump pad, a metalin which a first metal layer (barrier metal), a second metal layer ofcobalt (Co), and a third metal layer of copper (Cu) are sequentiallylaminated on a pad of aluminum (Al), is disposed. By reflow solderingbeing performed while the first and the second semiconductor chips arepositioned at positions where the microbump faces the bump pad, themicrobump is bonded to the metal disposed at the bump pad. By thismeans, the second semiconductor chip is implemented on the firstsemiconductor chip (see, for example, Patent Document 1).

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2017-079281

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In the above-described related art, there is a problem that strength ofa solder connection portion after implementation is low. In accordancewith reduction in a size of a semiconductor chip, increase in connectionportions in association with increase of signal lines, or the like, inrecent years, a pad to be formed on a semiconductor chip becomessmaller. In a case where a pad becomes smaller in this manner, becausethe solder connection portion becomes smaller, there is a problem thatstrength of the solder connection portion becomes lower in theabove-described related art.

The present technology has been made in view of the above-describedproblem, and is directed to improving solder connection strength even ina case where a pad becomes smaller.

Solutions to Problems

The present technology has been made in view of the above-describedproblem, and according to a first aspect of the present technology,there is provided a semiconductor device including a pad including aconcave portion on a surface, and at which solder connection is to beperformed, a diffusion layer disposed at the concave portion andconstituted with a metal which remains on the surface of the pad whilediffusing into solder upon the solder connection, and a melting layerdisposed adjacent to the diffusion layer and constituted with a metalwhich diffuses and melts into the solder upon the solder connection. Bythis means, action is provided that a diffusion layer remains betweenthe pad and the solder even after a melting layer at a concave portionof the pad melts into the solder upon solder connection. Here, diffusioncorresponds to intrusion into the solder and formation of an alloy withthe solder. The melting layer is replaced with the solder at the concaveportion of the pad while contact between the pad and the solder isprevented, and introduction of the solder into the concave portion ofthe pad is expected.

Further, in this first aspect, a diffusion prevention layer disposedbetween the pad and the diffusion layer described above and constitutedwith a metal which prevents diffusion of the pad into the solder uponthe solder connection is further included, and the diffusion layer mayremain on a surface of the diffusion prevention layer upon the solderconnection. By this means, action is provided that diffusion of the padwithin the solder upon solder connection is prevented.

Further, in this first aspect, the pad described above may include aplurality of the concave portions constituted in a linear shape. By thismeans, action is provided that the concave portion of the pad isconstituted with a plurality of grooves. Increase in a connection areafor solder connection is expected.

Further, in this first aspect, the pad described above may beconstituted with aluminum. By this means, action is provided that solderconnection is performed with the pad constituted with aluminum.

Further, in this first aspect, the pad described above may beconstituted with copper. By this means, action is provided that solderconnection is performed with the pad constituted with copper.

Further, in this first aspect, the diffusion layer described above maybe constituted with cobalt. By this means, action is provided that thediffusion layer constituted with cobalt remains on a surface of the padwhile diffusing within the solder upon solder connection.

Further, in this first aspect, the melting layer described above may beconstituted such that a plane different from a plane adjacent to thediffusion layer described above, has a flat planar shape. By this means,action is provided that a surface which contacts the solder upon solderconnection is planarized. Uniform contact between the solder and themelting layer is expected.

Further, according to a second aspect of the present technology, thereis provided a manufacturing method of a semiconductor device including aconcave portion forming step of forming a concave portion on a surfaceof a pad at which solder connection is to be performed, a diffusionlayer forming step of forming a diffusion layer constituted with a metalwhich remains on the surface of the pad while diffusing into solder uponthe solder connection, at the formed concave portion, and a meltinglayer forming step of forming a melting layer constituted with a metalwhich diffuses and melts into the solder upon the solder connection,adjacent to the formed diffusion layer. Action is provided that themelting layer at the concave portion of the pad melts into the solderupon solder connection, and a semiconductor device in which thediffusion layer remains between the pad and the solder is manufactured.The melting layer is replaced with the solder at the concave portion ofthe pad while contact between the pad and the solder is prevented, andintroduction of the solder into the concave portion is expected.

Effects of the Invention

The semiconductor device according to the present technology provides anexcellent effect that connection strength in solder connection isimproved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a configuration example of asemiconductor device according to a first embodiment of the presenttechnology.

FIG. 2 is a diagram illustrating a configuration example of asemiconductor device according to the first embodiment of the presenttechnology.

FIGS. 3A and 3B are diagrams illustrating a configuration example of apad according to the first embodiment of the present technology.

FIG. 4 is a diagram illustrating a configuration example of a padaccording to the first embodiment of the present technology.

FIGS. 5A, 5B, and 5C are diagrams illustrating an example of solderconnection according to the first embodiment of the present technology.

FIGS. 6A, 6B, 6C, and 6D are diagrams illustrating an example of amanufacturing method of a pad according to the first embodiment of thepresent technology.

FIGS. 7A, 7B, and 7C are diagrams illustrating an example of amanufacturing method of a pad according to the first embodiment of thepresent technology.

FIGS. 8A, 8B, and 8C are diagrams illustrating another example of themanufacturing method of the pad according to the first embodiment of thepresent technology.

FIG. 9 is a diagram illustrating a configuration example of a padaccording to a second embodiment of the present technology.

FIGS. 10A, 10B, 10C, and 10D are diagrams illustrating an example of amanufacturing method of a pad according to the second embodiment of thepresent technology.

FIGS. 11A, 11B, and 11C are diagrams illustrating an example of amanufacturing method of a pad according to the second embodiment of thepresent technology.

FIGS. 12A, 12B, and 12C are diagrams illustrating an example of amanufacturing method of a pad according to the second embodiment of thepresent technology.

FIG. 13 is a diagram illustrating a configuration example of a padaccording to a third embodiment of the present technology.

FIGS. 14A, 14B, 14C, and 14D are diagrams illustrating a configurationexample of a pad according to a modified example of the embodiments ofthe present technology.

FIG. 15 is a cross-sectional diagram illustrating a configurationexample of an imaging device to which the present technology can beapplied.

FIG. 16 is a view depicting an example of a schematic configuration ofan endoscopic surgery system.

FIG. 17 is a block diagram depicting an example of a functionalconfiguration of a camera head and a camera control unit (CCU).

FIG. 18 is a block diagram depicting an example of schematicconfiguration of a vehicle control system.

FIG. 19 is a diagram of assistance in explaining an example ofinstallation positions of an outside-vehicle information detectingsection and an imaging unit.

MODE FOR CARRYING OUT THE INVENTION

Next, a mode for implementing the present technology (hereinafterreferred to as an embodiment) will be described with reference to thedrawings. In the following drawings, the same or similar reference signsare attached to the same or similar portions. However, the drawings areschematic, and ratios of dimensions of each unit and the like do notnecessarily match the actual ones. In addition, of course, the drawingsalso include portions having different dimensional relationships andratios. In addition, the description of the embodiments will be given inthe following sequence.

-   -   1. First Embodiment    -   2. Second Embodiment    -   3. Third Embodiment    -   4. Modified examples    -   5. Application example to imaging device    -   6. Application example to endoscopic surgery system    -   7. Application example to mobile object

1. FIRST EMBODIMENT Configuration Example of Semiconductor Device

FIG. 1 is a diagram illustrating a configuration example of asemiconductor device according to a first embodiment of the presenttechnology. FIG. 1 is a diagram illustrating a configuration example ofa semiconductor device 10. This semiconductor device 10 is an imagingdevice having an imaging function of converting light from a subjectinto an image signal. The semiconductor device according to the firstembodiment of the present technology will be described using an exampleof this imaging device. The semiconductor device 10 includes a pixelchip 100 and a signal processing chip 200.

The pixel chip 100 is a semiconductor chip in which pixels whichgenerate image signals in accordance with radiated light are arranged ina two-dimensional grid shape. These pixels are arranged in a pixel arrayunit 110 in FIG. 1 . If light from the subject is focused on the pixelarray unit 110 via an imaging lens, an image signal in accordance withthe subject is generated for each pixel and output. The pixel includes aphotoelectric conversion unit which generates an electric charge inaccordance with the radiated light, and a pixel circuit which generatesan image signal on the basis of the electric charge generated by thephotoelectric conversion unit.

The signal processing chip 200 is a semiconductor chip which processesthe image signal generated by the pixel of the pixel chip 100. Thissignal processing chip 200 performs, for example, analog-digitalconversion of converting the analog image signal generated by the pixelinto a digital image signal, as signal processing. Thereafter, thedigital image signal is output for each frame which is an image signalcorresponding to one screen. Further, the signal processing chip 200generates a pixel control signal for controlling generation of the imagesignal at the pixel on the basis of a control signal input from outsideof the semiconductor device 10 and supplies the pixel control signal tothe pixel chip 100.

The signal processing chips 200 are respectively disposed along sideswhich face each other, of a surface on which the pixel array unit 110 isdisposed at the pixel chip 100. Specifically, the signal processing chip200 is implemented on the pixel chip 100 through solder connection. Theabove-described control signal is input once to the pixel chip 100 froman image processing device, or the like, outside the semiconductordevice 10, and transmitted to the signal processing chip 200 throughsolder connection. The pixel control signal based on the control signalis generated at the signal processing chip 200, transmitted again to thepixel chip 100 through solder connection, and input to each pixel of thepixel array unit 110. Meanwhile, the image signal generated by the pixelof the pixel array unit 110 is transmitted to the signal processing chip200 through solder connection. This transmitted image signal issubjected to signal processing at the signal processing chip 200,transmitted again to the pixel chip 100 through solder connection, andoutput to an image processing device outside the semiconductor device 10from the pixel chip 100.

Configuration Example of Semiconductor Device

FIG. 2 is a diagram illustrating a configuration example of asemiconductor device according to the first embodiment of the presenttechnology. FIG. 2 is a cross-sectional diagram schematicallyillustrating a configuration example of the semiconductor device 10. Thepixel chip 100 in FIG. 2 includes a semiconductor substrate 111,insulating layers 121 and 141, wiring layers 122, 142 and 143, pads 131to 133, a planarizing film 151, a color filter 152, an on-chip lens 153and a support substrate 113.

The semiconductor substrate 111 is a semiconductor substrate on which aphotoelectric conversion unit of the pixel of the pixel array unit 110and a semiconductor portion of the pixel circuit are formed. FIG. 2illustrates the photoelectric conversion unit as an example. A region112 in FIG. 2 is a semiconductor region formed in a diffusion region ofthe semiconductor substrate 111, and is a region where a photodiodewhich operates as the photoelectric conversion unit is formed. Theon-chip lens 153 is a lens which focuses light from a subject to theabove-described photoelectric conversion unit. The color filter 152 isan optical filter which transmits light of a predetermined wavelengthamong the light focused by the on-chip lens 153. The planarizing film151 planarizes a surface on which the color filter 152 is to be formedto make a film thickness of the color filter 152 uniform. The pixel chip100 in FIG. 2 corresponds to a rear surface irradiation type imagingelement in which the on-chip lens 153, or the like, are disposed on arear surface of the semiconductor substrate 111. The image signal isgenerated at the pixel on the basis of the light radiated from the rearsurface of the semiconductor substrate 111, and transmitted by a wiringlayer 122 disposed on a surface of the semiconductor substrate 111. Notethat the support substrate 113 is a substrate which is disposed on asurface of the semiconductor substrate 111 on which the insulating layer121 and the wiring layer 122 are formed, and which supports thesemiconductor substrate 111 upon processing on a rear surface side ofthe semiconductor substrate 111 or upon formation of the color filter152, or the like.

The wiring layers 122, 142 and 143 are wirings which transmit the imagesignal, the pixel control signal, or the like. Further, the insulatinglayers 121 and 141 insulate the wiring layer 122, or the like. Thewiring layer 122 and the insulating layer 121 are disposed on a surfaceside of the semiconductor substrate 111, and the wiring layers 142 and143 and the insulating layer 141 are disposed on the rear surface sideof the semiconductor substrate 111. Further, the wiring layer 122, orthe like, can be a multilayer wiring. FIG. 2 illustrates an examplewhere the wiring layer 122 is constituted to have three layers. Thewiring layers 122 formed in different layers can be connected with viaplugs 123. Note that the wiring layer 122 is connected to the wiringlayer 142 with a via plug 124. This via plug 124 is a via plug formed topenetrate through the semiconductor substrate 111, and is referred to asa through silicon via (TSV). The wiring layer 122, or the like, can beconstituted with a metal such as, for example, Cu. The insulating layers121 and 141 can be constituted with an insulator of, for example,silicon oxide (SiO₂), or the like.

The pads 131 to 133 transmit signals to circuits outside the pixel chip100. Specifically, the pads 131 and 132 transmit signals to the signalprocessing chip 200. As illustrated in FIG. 2 , the pad 131 issolder-connected to the pad 132 using solder bumps 201 and 202 whichwill be described later. Meanwhile, the pad 133 transmits signals to alead frame, or the like, disposed outside the pixel chip 100. Asillustrated in FIG. 2 , at the pad 133, signals are transmitted via abonding wire 109. The pads 131 to 133 are solder-connected, or the like,via openings 101 to 103 formed in the insulating layer 141. These pads131 to 133 can be constituted with a metal such as, for example, Al.Note that, as will be described later, a concave portion 134 is formedon surfaces of the pads 131 and 132, and an underlaying metal (thediffusion layer 136 and the melting layer 137) for solder connection islaminated.

The signal processing chip 200 includes a semiconductor substrate 213,pads 231 and 232, an insulating layer 241, and solder bumps 201 and 202.The solder bumps 201 and 202 are respectively formed at the pads 231 and232.

The solder bumps 201 and 202 are bumps constituted with solder. Thesolder bumps 201 and 202 are respectively solder-connected to the pads131 and 132 of the pixel chip 100 when the signal processing chip 200 isimplemented on the pixel chip 100. As the solder bumps 201 and 202, forexample, Sn-based solder can be used. Here, Sn-based solder correspondsto solder in which silver (Ag), bismuth (Bi), Cu, indium (In), or thelike, are added to Sn. Specifically, the solder corresponds toSnAg-based, SnBi-based, SnCu-based, SnIn-based and SnAgCu-based solder.Solder connection can be performed by disposing the signal processingchip 200 so as to face the pixel chip 100 while positioning the solderbumps 201 and 202 and the pads 131 and 132, and performing reflowsoldering. Note that description of the semiconductor substrate, thewiring layer, or the like, at the signal processing chip 200 has beenomitted.

In FIG. 2 , a signal flow path will be described using an example of animage signal. The image signal generated at the pixel array unit 110 istransmitted to a processing circuit of the signal processing chip 200 byway of the wiring layer 122, the via plug 124, the wiring layer 142, thepad 131, the solder bump 201 and the pad 231. Thereafter, the imagesignal processed by the processing circuit of the signal processing chip200 is output to outside of the pixel chip 100 by way of the pad 232,the solder bump 202, the pad 132, the wiring layer 143, the pad 133 andthe bonding wire 109.

[Configuration of Pad Portion]

FIGS. 3A and 3B are diagrams illustrating a configuration example of apad according to the first embodiment of the present technology. FIGS.3A and 3B are top views illustrating a configuration of the pad 131. Theconfiguration of the pad will be described using an example of the pad131. FIG. 3A illustrates a configuration of a surface of the pad 131 atthe opening 101 formed in the insulating layer 141 described in FIG. 2 .Note that the opening 101 in FIGS. 3A and 3B are constituted in anoctagon shape, and solder connection is performed at this opening.Therefore, a shape of the opening 101 corresponds to a shape of the pad131 relating to solder connection.

A concave portion is formed on the surface of the pad 131. Rectanglesindicated with a dashed line in FIGS. 3A and 3B are rectanglesindicating a boundary 135 of the concave portion of the pad 131. FIG. 3Bis an enlarged view of the pad 131 in FIG. 3A, and is a diagramillustrating a region 301 in FIG. 3A. In FIG. 3B, a region outside theboundary 135 indicates the concave portion 134 of the pad 131. FIGS. 3Aand 3B illustrate an example where a plurality of concave portionsconstituted in a linear shape is arranged. That is, the concave portion134 in FIGS. 3A and 3B indicate an example where a plurality of linearconcave portions is arranged longitudinally and transversely and formedin a net shape.

FIG. 4 is a diagram illustrating a configuration example of the padaccording to the first embodiment of the present technology. FIG. 4 is across-sectional diagram illustrating the configuration of the pad 131,and is a diagram illustrating a cross-section along a line A-A′ in FIG.3B. As illustrated in FIGS. 3A and 3B, the concave portion 134 is formedon the surface of the pad 131. Further, the diffusion layer 136 and themelting layer 137 are sequentially disposed adjacent to the pad 131including this concave portion 134. That is, these diffusion layer 136and melting layer 137 are disposed at the concave portion 134. Uponsolder connection, a molten solder bump 201 contacts the melting layer137. Note that a width and a depth of the concave portion 134 can be setat, for example, several hundred nm to several μm.

The diffusion layer 136 and the melting layer 137 can be bothconstituted with a metal which diffuses within the solder bump 201 uponsolder connection with the solder bump 201. The melting layer 137diffuses and melts into the solder bump 201 upon solder connection. Thatis, the melting layer 137 widely diffuses within the solder bump 201,and substantially disappears from the surface of the pad 131 after thesolder connection. Meanwhile, an amount of diffusion of the diffusionlayer 136 into the solder bump 201 is less than that of the meltinglayer 137, and the diffusion layer 136 remains on the surface of the pad131 even after the solder connection.

As described above in FIG. 2 , the pad 131 can be constituted with Al.Because this Al diffuses into the solder which constitutes the solderbump 201, or the like, upon solder connection, a thickness of the pad131 is reduced after the solder connection, and strength in the solderconnection is lowered. Therefore, by disposing the diffusion layer 136which remains on the surface of the pad 131 even after the solderconnection between the pad 131 and molten solder upon solder connection,it is possible to prevent contact between the pad 131 and the moltensolder, so that it is possible to prevent diffusion of the pad 131 intothe solder bump 201. Further, because a small amount of the diffusionlayer 136 diffuses into the solder bump 201 and forms an alloy, it ispossible to improve adhesion strength with the solder bump 201, or thelike.

In contrast, the melting layer 137 diffuses and disappears while formingan alloy between the melting layer 137 and the solder upon solderconnection as described above. Therefore, the state becomes a statewhere a region of the melting layer 137 illustrated in FIG. 2 isreplaced with molten solder. Even in such a case, contact between thepad 131 and the molten solder is prevented by the above-described actionof the diffusion layer 136. After the solder connection, the statebecomes a state where solder which constitutes the solder bump 201 isdisposed at the concave portion 134 formed on the surface of the pad131. That is, the state becomes a state where solder which constitutesthe solder bump 201, or the like, is introduced into the concave portion134 by the melting layer 137. Because a bonding area between the solderbump 201, or the like, and the pad 131 increases, it is possible toimprove strength of the solder connection. Further, because the concaveportion 134 exists at the solder connection portion, it is also possibleto improve strength against stress in a horizontal direction.

Further, as illustrated in FIG. 4 , by constituting the surface of themelting layer 137 to have a flat surface, it is possible to improvestrength in soldering. This is because the molten solder uniformlycontacts the melting layer 137, so that it is possible to preventoccurrence of a void at an interface between the molten solder bumps 201and 202 and the melting layer 137.

As the melting layer 137, for example, Cu and nickel (Ni) can be used.Further, as the diffusion layer 136, for example, Co, gold (Au) andplatinum (Pt) can be used. Among these, because Co less diffuses toSn-based solder, if Co is applied as the diffusion layer 136, it ispossible to make a film thickness of the diffusion layer 136 thinner.Therefore, it is possible to form the diffusion layer 136 through waferprocess. Further, by employing Cu as the melting layer 137, it ispossible to also form the melting layer 137 through wafer process. Notethat Ni can be also applied as the diffusion layer 136. In this event,Cu is employed as the melting layer 137.

[Solder Connection]

FIGS. 5A, 5B, and 5C are diagrams illustrating an example of solderconnection according to the first embodiment of the present technology.FIG. 5A is a diagram for explaining aspect of solder connection. Asindicated with an outline arrow in FIG. 5A, the solder bump 201 ispositioned on and contacts the surface of the pad 131, and reflowsoldering is performed. FIG. 5B is a diagram illustrating aspect of abonding portion in an initial stage of soldering, and is a diagramillustrating a state where the solder bump 201 which is molten by reflowsoldering contacts the melting layer 137. The molten solder bump 201contacts the melting layer 137, and the melting layer 137 diffuses intothe solder bump 201, thereby an alloy layer 203 is formed at aninterface of the solder bump 201 and the melting layer 137. This alloylayer 203 grows in accordance with diffusion of the melting layer 137.At the same time, the melting layer 137 gradually disappears. Aftersolder connection, the diffusion layer 136 which has been disposed atthe concave portion 134 is replaced with solder or the alloy layer 203.FIG. 5C is a diagram illustrating aspect of a bonding portion after thesolder connection, and is a diagram illustrating a state where the alloylayer 203 is introduced into the concave portion 134.

Note that also at the pad 231 of the signal processing chip 200, a metallayer 236 as an underlying metal is disposed. By forming a layer ofsolder on this metal layer 236, and cooling the layer of the solderafter melting the layer of the solder by reflow furnace, or the like, itis possible to form a solder bump 201 in a semisphere shape. As themetal layer 236, Ni can be used. Ni has characteristics that an amountof diffusion into solder is larger than that of Co described above.Therefore, by increasing a film thickness of the metal layer 236 usingNi, it is possible to cause the metal layer 236 to remain on a surfaceof the pad 231 after solder connection. However, there is a problemthat, because concavities and convexities by the metal layer 236 occuron the surface of the signal processing chip 200, the metal layer 236using Ni cannot be applied to a semiconductor device having a step offorming the color filter 152, or the like, like a pixel chip 100.

[Manufacturing Method of Pad Portion]

FIGS. 6A, 6B, 6C, 6D, 7A, 7B, and 7C are diagrams illustrating anexample of a manufacturing method of the pad according to the firstembodiment of the present technology. The manufacturing process of thepad 131 will be described using FIGS. 6A, 6B, 6C, 6D, 7A, 7B, and 7C. Inthe semiconductor substrate 111 on which the insulating layer 121, thewiring layer 122 and the support substrate 113 are disposed on itssurface, and the insulating layer 141, the wiring layer 142 and the pad131 are disposed on its rear surface, a resist 311 is formed on asurface of the insulating layer 141. This resist 311 is formed in ashape of the opening 101 through photolithography (FIG. 6A). Then, dryetching is performed on the insulating layer 141, and the resist 311 isremoved after etching. By this means, the opening 101 is formed in theinsulating layer 141 (FIG. 6B). Then, a resist 312 having a shape of theconcave portion 134 is formed (FIG. 6C). Then, dry etching and removalof the resist 312 are sequentially performed on the pad 131. By thismeans, the concave portion 134 is formed on the surface of the pad 131(FIG. 6D). This step corresponds to a concave portion forming steprecited in the claims.

Then, a metal film 313 constituting the diffusion layer 136 is formed(FIG. 7A). This metal film 313 can be formed through sputtering. Thisstep corresponds to a diffusion layer forming step recited in theclaims. Then, a metal film 314 constituting the melting layer 137 isformed (FIG. 7B). This metal film 314 can be formed by forming a seedlayer through sputtering and performing electrolytic plating. This stepcorresponds to a melting layer forming step recited in the claims.Finally, chemical mechanical polishing (CMP) is performed to planarize asurface of the melting layer 137 and remove the diffusion layer 136 andthe melting layer 137 disposed in a region other than the opening 101(FIG. 7C). By this means, it is possible to manufacture the pad 131 inwhich the diffusion layer 136 and the melting layer 137 are disposed atthe concave portion 134. Further, it is possible to form the diffusionlayer 136 and the melting layer 137 through wafer process.

[Other Manufacturing Method of Pad Portion]

FIGS. 8A, 8B, and 8C are diagrams illustrating another example of themanufacturing method of the pad according to the first embodiment of thepresent technology. The semiconductor substrate 111 in FIGS. 8A, 8B, and8C are different from the semiconductor substrate 111 described above inthat the wiring layer 142 is constituted in a shape similar to that ofthe concave portion 134. In a similar manner to the manufacturing methoddescribed in FIGS. 6A, 6B, 6C, and 6D, the opening 101 is formed in theinsulating layer 141 (FIG. 8A), and the resist 312 is formed (FIG. 8B).Then, in a similar manner to FIG. 6D, dry etching is performed (FIG.8C). In this event, the wiring layer 142 is used as a stopper layer indry etching. By this means, it is possible to simplify setting of a dryetching condition.

As described above, in the semiconductor device 10 in the firstembodiment of the present technology, by forming the concave portion 134at the pad 131 and disposing the diffusion layer 136 and the meltinglayer 137 at this concave portion 134, it is possible to improve solderconnection strength.

2. SECOND EMBODIMENT

In the semiconductor device 10 in the above-described first embodiment,the pad 131 constituted with Al is used. In contrast, the semiconductordevice 10 in a second embodiment of the present technology is differentfrom the semiconductor device 10 in the first embodiment in that the pad131 constituted with Cu is used.

[Configuration of Pad Portion]

FIG. 9 is a diagram illustrating a configuration example of a padaccording to a second embodiment of the present technology. FIG. 9 is across-sectional diagram illustrating a configuration of the pad 131. Thepad 131 in FIG. 9 is different from the pad 131 described in FIG. 4 inthe following points. The pad 131 in FIG. 9 is constituted with Cu in asimilar manner to the wiring layer 142. Further, the wiring layer 142 inFIG. 9 is constituted in the same shape as that of the concave portion134 of the pad 131, specifically, constituted in a net shape.

[Manufacturing Method of Pad Portion]

FIGS. 10A, 10B, 10C, 10D, 11A, 11B, 11C, 12A, 12B, and 12C are diagramsillustrating an example of the manufacturing method of the pad accordingto the second embodiment of the present technology. FIGS. 10A, 10B, 10C,10D, 11A, 11B, 11C, 12A, 12B, and 12C are diagrams illustrating amanufacturing process of the wiring layer 142 and the pad 131. First,the wiring layer 142 is formed inside the insulating layer 141. This canbe formed, for example, by forming a metal film (Cu) which becomes amaterial of the wiring layer 142 on the insulating layer 141 throughplating and performing patterning, and further laminating the insulatinglayer 141 (FIG. 10A). Then, a resist 316 is formed on the insulatinglayer 141. This resist 316 is constituted to have a shape of a patterninverse to that of the concave portion 134 (FIG. 10B). Then, theinsulating layer 141 is etched through dry etching (FIG. 10C). Then, themetal film 317 constituted with Cu is formed through plating (FIG. 10D).Then, the surface is ground through CMP, and the pad 131 is formed (FIG.11A).

Then, the insulating layer 141 is formed (FIG. 11B), and a resist 318having the same shape as that of the opening 101 is formed (FIG. 11C).Then, dry etching is performed, and the concave portion 134 is formed atthe pad 131 (FIG. 12A). Then, the diffusion layer 136 and the meltinglayer 137 are sequentially formed through sputtering (FIG. 12B).Finally, grinding is performed through CMP to planarize the surface ofthe melting layer 137 and remove the diffusion layer 136 and the meltinglayer 137 disposed in a region other than the opening 101 (FIG. 12C). Bythis means, it is possible to manufacture the pad 131 constituted withCu. In this manner, it is possible to form the pad 131 using a platingmethod which is similar to the method for the wiring layer 142.

Because a configuration of the semiconductor device 10 other than thisis similar to the configuration of the semiconductor device 10 describedin the first embodiment of the present technology, description will beomitted.

As described above, in the semiconductor device 10 in the secondembodiment of the present technology, the pad 131 is constituted with Cuand formed using a manufacturing method similar to the method for thewiring layer 142. By this means, it is possible to form the pad 131 andthe wiring layer 142 using a common manufacturing method, so that it ispossible to simplify the manufacturing process.

3. THIRD EMBODIMENT

In the semiconductor device 10 in the first embodiment described above,two metal layers (the diffusion layer 136 and the melting layer 137) areused as an underlying metal upon solder connection. In contrast, thesemiconductor device 10 in a third embodiment of the present technologyis different from the semiconductor device 10 in the first embodiment inthat a third metal layer is further provided.

[Configuration of Pad Portion]

FIG. 13 is a diagram illustrating a configuration example of a padaccording to a third embodiment of the present technology. FIG. 13 is across-sectional diagram illustrating a configuration example of the pad131. The pad 131 in FIG. 13 is different from the pad 131 described inFIG. 4 in that a diffusion prevention layer 138 is disposed on thesurface of the concave portion 134.

The diffusion prevention layer 138 is disposed between the pad 131 andthe diffusion layer 136, and prevents diffusion of the pad 131 into thesolder bumps 201 and 202. This diffusion prevention layer 138 isconstituted with a metal which does not cause diffusion into the solderbump 201, or the like, which is molten upon solder connection.Therefore, it is possible to prevent contact between an alloy of solderand the metal constituting the diffusion layer 136, and the pad 131 uponsolder connection, so that it is possible to protect the pad 131 frommolten solder, or the like. Further, by disposing the diffusionprevention layer 138 between the pad 131 and the diffusion layer 136, itis possible to improve adhesion strength between the pad 131 and theunderlying metal. As this diffusion prevention layer 138, for example,titanium (Ti), titanium nitride (TiN), tantalum (Ta) and tantalumnitride (TaN) can be used.

Further, it is preferable to constitute the diffusion prevention layer138 by sequentially laminating Ti and TiN on the surface of the pad 131.Ti has relatively high adhesion strength with Al, or the like, whichconstitute the pad 131. Meanwhile, because an oxide film is easilyformed on a surface of Ti, adhesion strength with the diffusion layer136 becomes relatively lower. In contrast, because TiN is chemicallystable, by successively forming a Ti layer and a TiN layer throughsputtering, it is possible to improve adhesion strength between the pad131 and the diffusion prevention layer 138, and between the diffusionprevention layer 138 and the diffusion layer 136. Note that it ispossible to realize a configuration of Ta+TaN by sequentially laminatingTa and TaN on the surface of the pad 131 in a similar manner.

Because a configuration of the semiconductor device 10 other than thisis similar to the configuration of the semiconductor device 10 describedin the first embodiment of the present technology, description will beomitted.

As described above, in the semiconductor device 10 in the thirdembodiment of the present technology, by disposing the diffusionprevention layer 138 between the pad 131 and the diffusion layer 136, itis possible to improve adhesion strength between the pad 131 and theunderlying metal while protecting the pad 131.

4. MODIFIED EXAMPLE

While, in the semiconductor device 10 in the first embodiment describedabove, the concave portion 134 in a net shape is formed on the pad 131,it is also possible to form the concave portion 134 having other shapes.

[Configuration of Pad Portion]

FIGS. 14A, 14B, 14C, and 14D are diagrams illustrating a configurationexample of a pad according to a modified example of the embodiments ofthe present technology. FIGS. 14A and 14B are top views illustrating aconfiguration example of the pad 131, and FIGS. 14C and 14D arecross-sectional diagrams illustrating a configuration example of the pad131.

The pad 131 in FIG. 14A includes the concave portion 134 in a circularshape. Further, this concave portion 134 is constituted in a shape of aconcentric circle. Further, FIG. 14B illustrates an example where thepad 131 has the concave portion 134 which is constituted in an octagonshape which is the same as the shape of the opening 101. In this manner,by simplifying the shape of the concave portion 134, it is possible tosimplify manufacturing of the pad 131.

The pad 131 in FIGS. 14C and 14D are constituted to have a cross-sectionin a tapered shape. The pad 131 in FIG. 14C is constituted have across-section in a forward tapered shape. Therefore, it is possible toeasily form the pad 131. Meanwhile, the pad 131 in FIG. 14D isconstituted to have a cross-section in an inverse tapered shape. It ispossible to suppress peeling of the solder bumps 201 and 202 aftersolder connection, so that it is possible to improve strength.

5. APPLICATION EXAMPLE TO IMAGING DEVICE

The present technology can be applied to various semiconductor devices.For example, the present technology can be applied to theabove-described imaging device. A detailed configuration of the imagingdevice to which the present technology is applied will be described.

FIG. 15 is a cross-sectional diagram illustrating a configurationexample of an imaging device to which the present technology can beapplied. FIG. 15 is a diagram illustrating a detailed configurationexample of the pixel array unit 110 of the imaging device (semiconductordevice 10) described in FIG. 1 b.

In the solid-state imaging apparatus, a photodiode (PD) 20019 receivesincident light 20001 that enters from the back side (top side in thedrawing) of a semiconductor substrate 20018. A planarizing film 20013, acolor filter (CF) 20012, and a microlens 20011 are provided above the PD20019, a light receiving surface 20017 receives the incident light 20001sequentially passing through each of the above-mentioned components toperform photoelectric conversion.

For example, the PD 20019 has an n-type semiconductor region 20020formed as a charge storage region that stores electrical charges(electrons). In the PD 20019, the n-type semiconductor region 20020 islocated inside p-type semiconductor regions 20016 and 20041 of thesemiconductor substrate 20018. In the n-type semiconductor region 20020,provided on the surface side (underside) of the semiconductor substrate20018 is the p-type semiconductor region 20041 with a higherconcentration of impurities than on the back side (top side). In otherwords, the PD 20019 is configured as an HAD (Hole-Accumulation Diode)structure. On the top side and the underside of the n-type semiconductorregion 20020, the p-type semiconductor regions 20016 and 20041 areformed respectively to suppress the generation of a dark current.

Inside the semiconductor substrate 20018 is a pixel separating section20030 that electrically separates multiple pixels 20010. The PD 20019 islocated in a region partitioned by the pixel separating section 20030.In a case where the solid-state imaging apparatus is viewed from the topside in the drawing, the pixel separating section 20030 is interposed,for example, between the multiple pixels 20010 to form a grid-likepattern. The PD 20019 is located in a grid region partitioned by thepixel separating section 20030.

The anode of each PD 20019 is grounded. In the solid-state imagingapparatus, the signal charge (e.g., electrons) accumulated in the PD20019 is read via a transfer Tr (MOS FET) or the like, not depicted, andoutput as an electrical signal onto a vertical signal line (VSL), notdepicted.

A wiring layer 20050 is provided on that opposite surface (underside) ofthe semiconductor substrate 20018 which is opposite to the back side(top side) where each of the components such as a light blocking film20014, the CF 20012, and the microlens 20011 are located.

The wiring layer 20050 includes wiring 20051 and an insulating layer20052. In the insulating layer 20052, the wiring 20051 is formed so asto connect electrically with each element. The wiring layer 20050constitutes a so-called multilayer wiring layer in which an interlayerdielectric film making up the insulating layer 20052 and the wiring20051 are alternately layered multiple times. Here, the wiring 20051 isconstituted by wires connected with Trs for reading the electricalcharges from the PD 20019 of the transfer Tr or the like and by wiressuch as VSLs, the wires being layered with the insulating layer 20052interposed therebetween.

A support substrate 20061 is provided on that side of the wiring layer20050 which is opposite to the side where the PD 20019 is located. Forexample, a silicon semiconductor that is hundreds of μm thickconstitutes the support substrate 20061.

The light blocking film 20014 is provided on the back side (top side inthe drawing) of the semiconductor substrate 20018.

The light blocking film 20014 is configured to partially block theincident light 20001 that enters from above the semiconductor substrate20018 and continues back side of the semiconductor substrate 20018.

The light blocking film 20014 is provided above the pixel separatingsection 20030 located inside the semiconductor substrate 20018. Here,the light blocking film 20014 is configured in such a manner as toprotrude through an insulating film 20015 such as a silicon oxide filmonto the back side (top side) of the semiconductor substrate 20018. Onthe upper side of the PD 20019 in the semiconductor substrate 20018, bycontrast, the light blocking film 20014 is not provided so that theincident light 20001 enters the PD 20019 through an aperture.

That is, in a case where the solid-state imaging apparatus is viewedfrom the top side, the light blocking film 20014 forms a plane in agrid-like pattern. The apertures are thus formed that allow the incidentlight 20001 to continue toward the light receiving surface 20017.

The light blocking film 20014 includes a light blocking material thatblocks light. For example, the light blocking film 20014 is formed byalternately layering a titanium (Ti) film and a tungsten (W) film.Alternatively, the light blocking film 20014 may be formed, for example,by alternately layering a titanium nitride (TiN) film and a tungsten (W)film.

The light blocking film 20014 is covered with the planarizing film20013. The planarizing film 20013 is formed by use of an insulatingmaterial that lets light pass through.

The pixel separating section 20030 includes a groove section 20031, afixed charge film 20032, and an insulating film 20033.

On the back side (top side) of the semiconductor substrate 20018, thefixed charge film 20032 is formed to cover the groove section 20031 thatpartitions multiple pixels 20010.

Specifically, the fixed charge film 20032 is provided in a mannercovering the internal surface of the groove section 20031 with aconstant thickness, the groove section 20031 being formed on the backside (top side) of the semiconductor substrate 20018. In addition, theinsulating film 20033 is provided to fill (pack) the inside of thegroove section 20031 covered with the fixed charge film 20032.

Here, the fixed charge film 20032 is formed by use of a high dielectricmaterial that has negative fixed charges for suppressing the generationof a dark current from a positive charge (hole) storage region formed inan interface portion with the semiconductor substrate 20018. With thefixed charge film 20032 formed to carry negative fixed charges, thenegative fixed charges apply an electric field to the interface with thesemiconductor substrate 20018, thereby forming the positive charge(hole) storage region in the interface.

The fixed charge film 20032 may be formed, for example, using a hafniumoxide film (HfO₂ film), for example. Alternatively, the fixed chargefilm 20032 may be formed, for example, to include at least one of suchoxide elements as hafnium, zirconium, aluminum, tantalum, titanium,magnesium, yttrium, lanthanoid, or the like.

The present technology can thus be applied to the imaging devicedescribed above.

6. APPLICATION EXAMPLE TO ENDOSCOPIC SURGERY SYSTEM

A technology (present technology) according to an embodiment of thepresent disclosure can be applied to various products. For example, thetechnology according to an embodiment of the present disclosure may beapplied to an endoscopic surgery system.

FIG. 16 is a view depicting an example of a schematic configuration ofan endoscopic surgery system to which the technology according to anembodiment of the present disclosure (present technology) can beapplied.

In 10, a state is illustrated in which a surgeon (medical doctor) 11131is using an endoscopic surgery system 11000 to perform surgery for apatient 11132 on a patient bed 11133. As depicted, the endoscopicsurgery system 11000 includes an endoscope 11100, other surgical tools11110 such as a pneumoperitoneum tube 11111 and an energy device 11112,a supporting arm apparatus 11120 which supports the endoscope 11100thereon, and a cart 11200 on which various apparatus for endoscopicsurgery are mounted.

The endoscope 11100 includes a lens barrel 11101 having a region of apredetermined length from a distal end thereof to be inserted into abody cavity of the patient 11132, and a camera head 11102 connected to aproximal end of the lens barrel 11101. In the example depicted, theendoscope 11100 is depicted which is included as a rigid endoscopehaving the lens barrel 11101 of the hard type. However, the endoscope11100 may otherwise be included as a flexible endoscope having the lensbarrel of the flexible type.

The lens barrel 11101 has, at a distal end thereof, an opening in whichan objective lens is fitted. A light source apparatus 11203 is connectedto the endoscope 11100 such that light generated by the light sourceapparatus 11203 is introduced to a distal end of the lens barrel by alight guide extending in the inside of the lens barrel 11101 and isirradiated toward an observation target in a body cavity of the patient11132 through the objective lens. It is to be noted that the endoscope11100 may be a forward-viewing endoscope or may be an oblique-viewingendoscope or a side-viewing endoscope.

An optical system and an imaging element are provided in the inside ofthe camera head 11102 such that reflected light (observation light) fromthe observation target is condensed on the imaging element by theoptical system. The observation light is photo-electrically converted bythe imaging element to generate an electric signal corresponding to theobservation light, namely, an image signal corresponding to anobservation image. The image signal is transmitted as RAW data to acamera control unit (CCU) 11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU) or the like and integrally controls operation ofthe endoscope 11100 and a display apparatus 11202. Further, the CCU11201 receives an image signal from the camera head 11102 and performs,for the image signal, various image processes for displaying an imagebased on the image signal such as, for example, a development process(demosaic process).

The display apparatus 11202 displays thereon an image based on an imagesignal, for which the image processes have been performed by the CCU11201, under the control of the CCU 11201.

The light source apparatus 11203 includes a light source such as, forexample, a light emitting diode (LED) and supplies irradiation lightupon imaging of a surgical region and the like to the endoscope 11100.

An inputting apparatus 11204 is an input interface for the endoscopicsurgery system 11000. A user can perform inputting of various kinds ofinformation or instruction inputting to the endoscopic surgery system11000 through the inputting apparatus 11204. For example, the user wouldinput an instruction or the like to change an image pickup condition(type of irradiation light, magnification, focal distance or the like)by the endoscope 11100.

A treatment tool controlling apparatus 11205 controls driving of theenergy device 11112 for cautery or incision of a tissue, sealing of ablood vessel or the like. A pneumoperitoneum apparatus 11206 feeds gasinto a body cavity of the patient 11132 through the pneumoperitoneumtube 11111 to inflate the body cavity in order to secure the field ofview of the endoscope 11100 and secure the working space for thesurgeon. A recorder 11207 is an apparatus capable of recording variouskinds of information relating to surgery. A printer 11208 is anapparatus capable of printing various kinds of information relating tosurgery in various forms such as a text, an image or a graph.

It is to be noted that the light source apparatus 11203 which suppliesirradiation light when a surgical region is to be imaged to theendoscope 11100 may include a white light source which includes, forexample, an LED, a laser light source or a combination of them. Where awhite light source includes a combination of red, green, and blue (RGB)laser light sources, since the output intensity and the output timingcan be controlled with a high degree of accuracy for each color (eachwavelength), adjustment of the white balance of a picked up image can beperformed by the light source apparatus 11203. Further, in this case, iflaser beams from the respective RGB laser light sources are irradiatedtime-divisionally on an observation target and driving of the imagingelements of the camera head 11102 are controlled in synchronism with theirradiation timings, it is also possible to time-divisionally captureimages corresponding to respective R, G and B. According to the methodjust described, a color image can be obtained even if a color filter isnot provided for the imaging element.

Further, the light source apparatus 11203 may be controlled such thatthe intensity of light to be outputted is changed for each predeterminedtime. By controlling driving of the imaging element of the camera head11102 in synchronism with the timing of the change of the intensity oflight to acquire images time-divisionally and synthesizing the images,an image of a high dynamic range free from underexposed blocked upshadows and overexposed highlights can be created.

Further, the light source apparatus 11203 may be configured to supplylight of a predetermined wavelength band ready for special lightobservation. In special light observation, for example, by utilizing thewavelength dependency of absorption of light in a body tissue toirradiate light of a narrower wavelength band in comparison withirradiation light upon ordinary observation (namely, white light),so-called narrow band light observation (narrow band imaging) of imaginga predetermined tissue such as a blood vessel of a superficial portionof the mucous membrane or the like in a high contrast is performed.Alternatively, in special light observation, fluorescent observation forobtaining an image from fluorescent light generated by irradiation ofexcitation light may be performed. In fluorescent observation, it ispossible to perform observation of fluorescent light from a body tissueby irradiating excitation light on the body tissue (autofluorescenceobservation) or to obtain a fluorescent light image by locally injectinga reagent such as indocyanine green (ICG) into a body tissue andirradiating excitation light corresponding to a fluorescent lightwavelength of the reagent upon the body tissue, for example. The lightsource apparatus 11203 can be configured to supply such narrow-bandlight and/or excitation light suitable for special light observation asdescribed above.

FIG. 17 is a block diagram depicting an example of a functionalconfiguration of the camera head 11102 and the CCU 11201 depicted inFIG. 16 .

The camera head 11102 includes a lens unit 11401, an imaging unit 11402,a driving unit 11403, a communication unit 11404 and a camera headcontrolling unit 11405. The CCU 11201 includes a communication unit11411, an image processing unit 11412 and a control unit 11413. Thecamera head 11102 and the CCU 11201 are connected for communication toeach other by a transmission cable 11400.

The lens unit 11401 is an optical system, provided at a connectinglocation to the lens barrel 11101. Observation light taken in from adistal end of the lens barrel 11101 is guided to the camera head 11102and introduced into the lens unit 11401. The lens unit 11401 includes acombination of a plurality of lenses including a zoom lens and afocusing lens.

The imaging unit 11402 includes imaging elements. The number of imagingelements which is included by the imaging unit 11402 may be one(so-called single-plate type) or a plural number (so-called multi-platetype). Where the imaging unit 11402 is configured as that of themulti-plate type, for example, image signals corresponding to respectiveR, G and B are generated by the imaging elements, and the image signalsmay be synthesized to obtain a color image. The imaging unit 11402 mayalso be configured so as to have a pair of imaging elements foracquiring respective image signals for the right eye and the left eyeready for three dimensional (3D) display. If 3D display is performed,then the depth of a living body tissue in a surgical region can becomprehended more accurately by the surgeon 11131. It is to be notedthat, in a case where the imaging unit 11402 is configured as that ofmulti-plate type, a plurality of systems of lens units 11401 is providedcorresponding to the individual imaging elements.

Further, the imaging unit 11402 may not necessarily be provided on thecamera head 11102. For example, the imaging unit 11402 may be providedimmediately behind the objective lens in the inside of the lens barrel11101.

The driving unit 11403 includes an actuator and moves the zoom lens andthe focusing lens of the lens unit 11401 by a predetermined distancealong an optical axis under the control of the camera head controllingunit 11405. Consequently, the magnification and the focal point of apicked up image by the imaging unit 11402 can be adjusted suitably.

The communication unit 11404 includes a communication apparatus fortransmitting and receiving various kinds of information to and from theCCU 11201. The communication unit 11404 transmits an image signalacquired from the imaging unit 11402 as RAW data to the CCU 11201through the transmission cable 11400.

In addition, the communication unit 11404 receives a control signal forcontrolling driving of the camera head 11102 from the CCU 11201 andsupplies the control signal to the camera head controlling unit 11405.The control signal includes information relating to imaging conditionssuch as, for example, information by which a frame rate of a picked upimage is designated, information by which an exposure value upon imagepicking up is designated and/or information by which a magnification anda focal point of a picked up image are designated.

It is to be noted that the image pickup conditions such as the framerate, exposure value, magnification or focal point may be appropriatelydesignated by the user or may be set automatically by the control unit11413 of the CCU 11201 on the basis of an acquired image signal. In thelatter case, an auto exposure (AE) function, an auto focus (AF) functionand an auto white balance (AWB) function are incorporated in theendoscope 11100.

The camera head controlling unit 11405 controls driving of the camerahead 11102 on the basis of a control signal from the CCU 11201 receivedthrough the communication unit 11404.

The communication unit 11411 includes a communication apparatus fortransmitting and receiving various kinds of information to and from thecamera head 11102. The communication unit 11411 receives an image signaltransmitted thereto from the camera head 11102 through the transmissioncable 11400.

Further, the communication unit 11411 transmits a control signal forcontrolling driving of the camera head 11102 to the camera head 11102.The image signal and the control signal can be transmitted by electricalcommunication, optical communication or the like.

The image processing unit 11412 performs various image processes for animage signal in the form of RAW data transmitted thereto from the camerahead 11102.

The control unit 11413 performs various kinds of control relating toimage picking up of a surgical region or the like by the endoscope 11100and display of a picked up image obtained by image picking up of thesurgical region or the like. For example, the control unit 11413 createsa control signal for controlling driving of the camera head 11102.

Further, the control unit 11413 controls, on the basis of an imagesignal for which image processes have been performed by the imageprocessing unit 11412, the display apparatus 11202 to display a pickedup image in which the surgical region or the like is imaged. Thereupon,the control unit 11413 may recognize various objects in the picked upimage using various image recognition technologies. For example, thecontrol unit 11413 can recognize a surgical tool such as forceps, aparticular living body region, bleeding, mist when the energy device11112 is used and so forth by detecting the shape, color and so forth ofedges of objects included in a picked up image. The control unit 11413may cause, when it controls the display apparatus 11202 to display apicked up image, various kinds of surgery supporting information to bedisplayed in an overlapping manner with an image of the surgical regionusing a result of the recognition. Where surgery supporting informationis displayed in an overlapping manner and presented to the surgeon11131, the burden on the surgeon 11131 can be reduced and the surgeon11131 can proceed with the surgery with certainty.

The transmission cable 11400 which connects the camera head 11102 andthe CCU 11201 to each other is an electric signal cable ready forcommunication of an electric signal, an optical fiber ready for opticalcommunication or a composite cable ready for both of electrical andoptical communications.

Here, while, in the example depicted, communication is performed bywired communication using the transmission cable 11400, thecommunication between the camera head 11102 and the CCU 11201 may beperformed by wireless communication.

The above description describes an example of an endoscopic surgerysystem to which the technology according to the present disclosure canbe applied. The technology according to the present disclosure can beapplied to the imaging unit 11402 of the camera head 11102 of theconstituent elements described above. Specifically, the semiconductordevice 10 in FIG. 1 can be applied to the imaging unit 10402, forexample. By applying the technology according to the present disclosureto the imaging unit 10402, it is possible to improve connection strengthin solder connection, so that it is possible to constitute an endoscopicsurgery system having high reliability.

Note that, here, an endoscopic surgery system is described as anexample, but the technology according to the present disclosure may beapplied to other systems such as a microsurgery system, for example.

7. APPLICATION EXAMPLE TO MOBILE OBJECT

A technology (present technology) according to an embodiment of thepresent disclosure can be applied to various products. For example, thetechnology according to the present disclosure may also be realized as adevice mounted in a mobile object of any type such as automobile,electric vehicle, hybrid electric vehicle, motorcycle, bicycle, personalmobility, airplane, drone, ship, or robot.

FIG. 18 is a block diagram depicting an example of schematicconfiguration of a vehicle control system as an example of a mobileobject control system to which the technology according to an embodimentof the present disclosure can be applied.

The vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example depicted in FIG. 18 , the vehicle control system 12000includes a driving system control unit 12010, a body system control unit12020, an outside-vehicle information detecting unit 12030, anin-vehicle information detecting unit 12040, and an integrated controlunit 12050. In addition, a microcomputer 12051, a sound/image outputsection 12052, and a vehicle-mounted network interface (I/F) 12053 areillustrated as a functional configuration of the integrated control unit12050.

The driving system control unit 12010 controls the operation of devicesrelated to the driving system of the vehicle in accordance with variouskinds of programs. For example, the driving system control unit 12010functions as a control device for a driving force generating device forgenerating the driving force of the vehicle, such as an internalcombustion engine, a driving motor, or the like, a driving forcetransmitting mechanism for transmitting the driving force to wheels, asteering mechanism for adjusting the steering angle of the vehicle, abraking device for generating the braking force of the vehicle, and thelike.

The body system control unit 12020 controls the operation of variouskinds of devices provided to a vehicle body in accordance with variouskinds of programs. For example, the body system control unit 12020functions as a control device for a keyless entry system, a smart keysystem, a power window device, or various kinds of lamps such as aheadlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or thelike. In this case, radio waves transmitted from a mobile device as analternative to a key or signals of various kinds of switches can beinput to the body system control unit 12020. The body system controlunit 12020 receives these input radio waves or signals, and controls adoor lock device, the power window device, the lamps, or the like of thevehicle.

The outside-vehicle information detecting unit 12030 detects informationabout the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicle information detecting unit 12030is connected with an imaging unit 12031. The outside-vehicle informationdetecting unit 12030 makes the imaging unit 12031 image an image of theoutside of the vehicle, and receives the imaged image. On the basis ofthe received image, the outside-vehicle information detecting unit 12030may perform processing of detecting an object such as a human, avehicle, an obstacle, a sign, a character on a road surface, or thelike, or processing of detecting a distance thereto.

The imaging unit 12031 is an optical sensor that receives light, andwhich outputs an electric signal corresponding to a received lightamount of the light. The imaging unit 12031 can output the electricsignal as an image, or can output the electric signal as informationabout a measured distance. In addition, the light received by theimaging unit 12031 may be visible light, or may be invisible light suchas infrared rays or the like.

The in-vehicle information detecting unit 12040 detects informationabout the inside of the vehicle. The in-vehicle information detectingunit 12040 is, for example, connected with a driver state detectingsection 12041 that detects the state of a driver. The driver statedetecting section 12041, for example, includes a camera that images thedriver. On the basis of detection information input from the driverstate detecting section 12041, the in-vehicle information detecting unit12040 may calculate a degree of fatigue of the driver or a degree ofconcentration of the driver, or may determine whether the driver isdozing.

The microcomputer 12051 can calculate a control target value for thedriving force generating device, the steering mechanism, or the brakingdevice on the basis of the information about the inside or outside ofthe vehicle which is obtained by the outside-vehicle informationdetecting unit 12030 or the in-vehicle information detecting unit 12040,and output a control command to the driving system control unit 12010.For example, the microcomputer 12051 can perform cooperative controlintended to implement functions of an advanced driver assistance system(ADAS) which include collision avoidance or shock mitigation for thevehicle, following driving based on a following distance, vehicle speedmaintaining driving, a warning of collision of the vehicle, a warning ofdeviation of the vehicle from a lane, or the like.

In addition, the microcomputer 12051 can perform cooperative controlintended for automatic driving, which makes the vehicle to travelautonomously without depending on the operation of the driver, or thelike, by controlling the driving force generating device, the steeringmechanism, the braking device, or the like on the basis of theinformation about the surroundings of the vehicle which is obtained bythe outside-vehicle information detecting unit 12030 or the in-vehicleinformation detecting unit 12040.

In addition, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of the information about theoutside of the vehicle which is obtained by the outside-vehicleinformation detecting unit 12030. For example, the microcomputer 12051can perform cooperative control intended to prevent a glare bycontrolling the headlamp so as to change from a high beam to a low beam,for example, in accordance with the position of a preceding vehicle oran oncoming vehicle detected by the outside-vehicle informationdetecting unit 12030.

The sound/image output section 12052 transmits an output signal of atleast one of a sound or an image to an output device capable of visuallyor auditorily notifying an occupant of the vehicle or the outside of thevehicle of information. In the example of FIG. 18 , an audio speaker12061, a display section 12062, and an instrument panel 12063 areillustrated as the output device. The display section 12062 may, forexample, include at least one of an on-board display and a head-updisplay.

FIG. 19 is a diagram depicting an example of the installation positionof the imaging unit 12031.

In FIG. 19 , the vehicle 12100 includes imaging units 12101, 12102,12103, 12104, and 12105 as the imaging unit 12031.

The imaging units 12101, 12102, 12103, 12104, and 12105 are, forexample, disposed at positions on a front nose, sideview mirrors, a rearbumper, and a back door of the vehicle 12100 as well as a position on anupper portion of a windshield within the interior of the vehicle. Theimaging unit 12101 provided to the front nose and the imaging unit 12105provided to the upper portion of the windshield within the interior ofthe vehicle obtain mainly an image of the front of the vehicle 12100.The imaging units 12102 and 12103 provided to the sideview mirrorsobtain mainly an image of the sides of the vehicle 12100. The imagingunit 12104 provided to the rear bumper or the back door obtains mainlyan image of the rear of the vehicle 12100. The images of the frontobtained by the imaging units 12101 and 12105 are used mainly to detecta preceding vehicle, a pedestrian, an obstacle, a signal, a trafficsign, a lane, or the like.

Incidentally, FIG. 19 depicts an example of imaging ranges of theimaging units 12101 to 12104. An imaging range 12111 represents theimaging range of the imaging unit 12101 provided to the front nose.Imaging ranges 12112 and 12113 respectively represent the imaging rangesof the imaging units 12102 and 12103 provided to the sideview mirrors.An imaging range 12114 represents the imaging range of the imaging unit12104 provided to the rear bumper or the back door. A bird's-eye imageof the vehicle 12100 as viewed from above is obtained by superimposingimage data imaged by the imaging units 12101 to 12104, for example.

At least one of the imaging units 12101 to 12104 may have a function ofobtaining distance information. For example, at least one of the imagingunits 12101 to 12104 may be a stereo camera constituted of a pluralityof imaging elements, or may be an imaging element having pixels forphase difference detection.

For example, the microcomputer 12051 can determine a distance to eachthree-dimensional object within the imaging ranges 12111 to 12114 and atemporal change in the distance (relative speed with respect to thevehicle 12100) on the basis of the distance information obtained fromthe imaging units 12101 to 12104, and thereby extract, as a precedingvehicle, a nearest three-dimensional object in particular that ispresent on a traveling path of the vehicle 12100 and which travels insubstantially the same direction as the vehicle 12100 at a predeterminedspeed (for example, equal to or more than 0 km/hour). Further, themicrocomputer 12051 can set a following distance to be maintained infront of a preceding vehicle in advance, and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), or the like. It is thuspossible to perform cooperative control intended for automatic drivingthat makes the vehicle travel autonomously without depending on theoperation of the driver or the like.

For example, the microcomputer 12051 can classify three-dimensionalobject data on three-dimensional objects into three-dimensional objectdata of a two-wheeled vehicle, a standard-sized vehicle, a large-sizedvehicle, a pedestrian, a utility pole, and other three-dimensionalobjects on the basis of the distance information obtained from theimaging units 12101 to 12104, extract the classified three-dimensionalobject data, and use the extracted three-dimensional object data forautomatic avoidance of an obstacle. For example, the microcomputer 12051identifies obstacles around the vehicle 12100 as obstacles that thedriver of the vehicle 12100 can recognize visually and obstacles thatare difficult for the driver of the vehicle 12100 to recognize visually.Then, the microcomputer 12051 determines a collision risk indicating arisk of collision with each obstacle. In a situation in which thecollision risk is equal to or higher than a set value and there is thusa possibility of collision, the microcomputer 12051 outputs a warning tothe driver via the audio speaker 12061 or the display section 12062, andperforms forced deceleration or avoidance steering via the drivingsystem control unit 12010. The microcomputer 12051 can thereby assist indriving to avoid collision.

At least one of the imaging units 12101 to 12104 may be an infraredcamera that detects infrared rays. The microcomputer 12051 can, forexample, recognize a pedestrian by determining whether or not there is apedestrian in imaged images of the imaging units 12101 to 12104. Suchrecognition of a pedestrian is, for example, performed by a procedure ofextracting characteristic points in the imaged images of the imagingunits 12101 to 12104 as infrared cameras and a procedure of determiningwhether or not it is the pedestrian by performing pattern matchingprocessing on a series of characteristic points representing the contourof the object. When the microcomputer 12051 determines that there is apedestrian in the imaged images of the imaging units 12101 to 12104, andthus recognizes the pedestrian, the sound/image output section 12052controls the display section 12062 so that a square contour line foremphasis is displayed so as to be superimposed on the recognizedpedestrian. In addition, the sound/image output section 12052 may alsocontrol the display section 12062 so that an icon or the likerepresenting the pedestrian is displayed at a desired position.

The above description describes an example of a vehicle control systemto which the technology according to the present disclosure can beapplied. The technology according to the present disclosure may beapplied to the imaging unit 12031 or the like among the configurationsdescribed above. Specifically, the semiconductor device 10 in FIG. 1 canbe applied to the imaging units 12031 and 12101 to 12105. By applyingthe technology according to the present disclosure to the imaging unit12031, or the like, it is possible to improve connection strength insolder connection, so that it is possible to constitute a vehiclecontrol system having high reliability.

Finally, the description of each of the embodiments described above isan example of the present technology, and the present technology is notlimited to the embodiments described above. Therefore, of course,various modifications are able to be made according to the design or thelike as long as the modifications do not depart from the technicalspirit according to the present technology, even if the modificationsare other than each of the embodiments described above.

Additionally, the present technology may also be configured as below.

(1) A semiconductor device including:

-   -   a pad including a concave portion on a surface, and at which        solder connection is to be performed;    -   a diffusion layer disposed at the concave portion and        constituted with a metal which remains on the surface of the pad        while diffusing into solder upon the solder connection; and    -   a melting layer disposed adjacent to the diffusion layer and        constituted with a metal which diffuses and melts into the        solder upon the solder connection.

(2) The semiconductor device according to (1), further including:

-   -   a diffusion prevention layer disposed between the pad and the        diffusion layer and constituted with a metal which prevents        diffusion of the pad into the solder upon the solder connection,    -   in which the diffusion layer remains on a surface of the        diffusion prevention layer upon the solder connection.

(3) The semiconductor device according to (1) or (2), in which the padincludes a plurality of the concave portions constituted in a linearshape.

(4) The semiconductor device according to any one of (1) to (3), inwhich the pad is constituted with aluminum.

(5) The semiconductor device according to any one of (1) to (3), inwhich the pad is constituted with copper.

(6) The semiconductor device according to any one of (1) to (5), inwhich the diffusion layer is constituted with cobalt.

(7) The semiconductor device according to any one of (1) to (6), inwhich the melting layer is constituted such that a plane different froma plane adjacent to the diffusion layer, has a flat planar shape.

(8) A manufacturing method of a semiconductor device including:

-   -   a concave portion forming step of forming a concave portion on a        surface of a pad at which solder connection is to be performed;    -   a diffusion layer forming step of forming a diffusion layer        constituted with a metal which remains on the surface of the pad        while diffusing into solder upon the solder connection, at the        formed concave portion; and    -   a melting layer forming step of forming a melting layer        constituted with a metal which diffuses and melts into the        solder upon the solder connection, adjacent to the formed        diffusion layer.

REFERENCE SIGNS LIST

-   -   10 Semiconductor device    -   100 Pixel chip    -   101 Opening    -   110 Pixel array unit    -   111, 213 Semiconductor substrate    -   121, 141 Insulating layer    -   122, 142, 143 Wiring layer    -   131 to 133, 231 Pad    -   134 Concave portion    -   136 Diffusion layer    -   137 Melting layer    -   138 Diffusion prevention layer    -   200 Signal processing chip    -   201, 202 Solder bump    -   10402, 12031, 12101 to 12105 imaging unit

1. A semiconductor device, comprising: a pad including a concave portionon a surface, wherein the pad is for a solder connection; a diffusionlayer at the concave portion, wherein the diffusion layer comprises afirst metal; a melting layer adjacent to the diffusion layer, whereinthe melting layer comprises a second metal, and the melting layerdiffuses and melts into the solder upon the solder connection; and adiffusion prevention layer between the pad and the diffusion layer,wherein the diffusion prevention layer comprises a third metal, thediffusion prevention layer prevents diffusion of the pad into the solderupon the solder connection, and the diffusion layer remains on a surfaceof the diffusion prevention layer upon the solder connection.
 2. Thesemiconductor device according to claim 1, wherein the diffusionprevention layer comprises one of titanium (Ti), titanium nitride (TiN),tantalum (Ta), or tantalum nitride (TaN).
 3. The semiconductor deviceaccording to claim 1, wherein the diffusion prevention layer comprisessequential lamination of Ti and TiN on the surface of the pad.
 4. Thesemiconductor device according to claim 1, wherein the pad includes aplurality of the concave portions constituted in a linear shape.
 5. Thesemiconductor device according to claim 1, wherein the pad comprisesaluminum.
 6. The semiconductor device according to claim 1, wherein thepad comprises copper.
 7. The semiconductor device according to claim 1,wherein the diffusion layer comprises cobalt.
 8. The semiconductordevice according to claim 1, wherein a surface of the melting layer hasa flat planar shape.